Vol. 2 No. 3 Sept 2021
Gregory J. Scaven | President, PacSci EMC
IS FAILURE THE NEW SUCCESS
Many of us in the industry recently watched Firefly Aerospace attempt to launch its Alpha vehicle into orbit from Vandenberg AFB. It’s probably important that I let everyone know I was mostly watching the launch since PacSci EMC had just recently successfully completed its qualification test program with its all-electronic Flight Termination System (FTS) with Firefly. While of course that was another major milestone for us at PacSci EMC, that’s not at all what this article is about. It’s more about the growth mindset that I followed on social media around the launch – and how important that is to assuring mission success for all of us both professionally as well as personally.
For those who know the story, Alpha didn’t make it to orbit. The flight was in fact terminated by Range Safety – the rocket did not explode on its own.
Firefly and other supporters in the industry celebrated the launch event and even dared to broadcast it live for thousands (or more) to witness. Of course, no one was happy that Alpha failed to make orbit – but less than one week after the launch, social media posts from the Firefly team and others in the industry celebrated the wealth of flight data that was collected from the mission – and they stated, “will greatly enhance the likelihood of Alpha achieving orbit during its second flight”.
I’ve talked before about the power of a growth mindset – and I think this is a great example of the type of culture I want to ensure we have at our company – and hopefully share with our valued customers and suppliers. As much as we all would love to be 100% successful in everything we do, I’ve yet to meet the person who has been.
In fact, how we handle
failure is probably a better indicator of how successful we will ultimately be in our lives and in our jobs than how we handle success. With failure should come the opportunity to learn…and learning is how we grow and become more confident while becoming more curious.
PacSci EMC, like all Fortive operating companies, has a formalized process for learning. We call it “problem solving” within our corporation, but it takes its root from teachings that make up the Toyota Production System. The MIT Sloan Management Review in its summer 2009 highlighted this process in an article entitled “Toyota’s Secret: The A3 Report”. Problem Solving Process, or PSP, focuses a lot of attention on defining the problem in a simple-to-understand statement. Defining the problem statement accurately and with gemba-based evidence helps us avoid jumping to conclusions based on simply strong emotional attachments. We go to gemba to “see”, not “feel”.
Once we nail down the problem statement, we attempt to quantify the gap required to get back to the desired condition. We’ll use a Pareto analysis
to define this gap – often by answering questions to further define what or where that makes up this gap. A lot of our creativity gets applied within this Pareto – as this is where we will challenge ourselves to come up with not just one Pareto, but several – in attempt to view the gap from different perspectives. Once we’ve selected a Pareto that we believe truly highlights our biggest opportunity to close the gap, we’ll then focus our energy on creating a second Pareto chart from the first that attempts to define why these biggest gaps from the first Pareto chart exist in the first place.
PSP of course doesn’t stop there. We’ll take this first why and then launch into asking ourselves why the first why exists and arrive at a second why, and then asking more why’s from there. I think of this part of our process – asking successive why’s – as akin to any robust root cause/corrective action (RC/CA) process most of us have as our accredited quality management systems. Arriving at the final why certainly represents an opportunity to learn, but I think the secret to growth – if you will, the growth mindset – lies in the next steps.
All too often this is where I see good process not so much break down, but grind to a halt. This last why is basically the root cause….and requires corrective action. Just as a team should challenge itself to arrive at different Pareto charts, the team needs to challenge itself to validate and verify the effectiveness of the proposed corrective action. Without proper verification, it’s possible that you haven’t arrived at either the true root cause or an effective countermeasure. This last step – verification – is all too often either skipped or forgotten but is critical to ensure that you don’t have to learn the very same lesson all over again.
Failure creates the opportunity to learn – and our problem-solving process guides our learning to ensure that we don’t repeat the same failures. We’re just as excited as the Firefly team for the second launch of Alpha – and look forward to contributing to future mission successes at all our customers as they learn and grow to take on new challenges.
THE TURN & BURN OF
START CARTRIDGES &
Peter Current | Director, New Product Development
At PacSci EMC we design and build for every environment. The following content is focused on an atmospheric application, start cartridges, and pyrotechnic igniters. We jokingly call it ‘turn and burn’ from the standpoint that the start cartridge gets the turbine up and spinning and the pyrotechnic igniter provides heat to light off the charged combustion chamber.
The way we approach the design of start cartridges or pyrotechnic igniters is nearly identical and very methodical, a kind of waterfall technique:
Start with calculation of what size cartridge is needed in
relation to the mechanical and physical requirement of
gas to get the turbine spinning.
Marry the initiation system, propellant and the output
Figure a way to fit it into the customers package size they need
The final step is integration into the engine
What is a Start Cartridge?
A start cartridge, or ‘start cart’, takes a firing impetus and spins up a turbine. Inside the cartridge we’re taking a low-level input from either a pyro line or an electric initiator to provide a significant amount of heat and pressure to then light off the propellant grain.
The propellant grain is a solid fuel, and it evolves off gas as it burns. That gas is what gets accelerated or pushed out the nozzle (Figure 1) to hit the turbine, getting it spinning. When the turbine is spinning, it will charge up the combustion chamber preparing it for ignition.
The first step in the process is to figure out what size cartridge you need in terms of energy. This requires assessing how much energy it is going to take to get the turbine up and spinning to the point it’s going to be stable for combustion in all situations.
To that end, customers look at the environmental extremes in terms of what temperature conditions the turbine is going to be working in. Also, the airflow over the inlet is evaluated, and whether there are covers that have to come off, the timing of those covers, etc. They also look at the angle of attack: if it’s dropping off a wing or coming out of the bay. Essentially, looking at the longest time those elements are going to take to spin up and charge the combustion chamber as it’s getting power. There are a lot of mechanical factors customers must consider that are part of their system. Things like the turbine efficiency from the blades, how fast the compressor can start pulling in air, and turbine inertia. The turbine is going to resist that rotational motion at the beginning, not just from lubrication and drag, but also from inertia. The gas from start cartridge provides the energy required to get the mechanical components up to speed.
With those inputs defined, we look at where we can impinge on the impeller, and from there figure out how much time and horsepower it’s going to take. Once the calculations are done, there are two ways of flowing the requirement down to us. The first is pressure and temperature at the output over that period of time, and that’s what you see in Figure 2. The graph is displaying a time pressure curve of the output of one of our units.
All this analysis is performed and refined to just inside the nozzle prior to the restriction. It’s a pressure over a given period of time. There’s a
temperature requirement that goes along with this as well. It’s essentially adiabatic flame temperature of the composition, a little bit lower, but it’s right there at the nozzle. This becomes the Pressure/Time/Temperature curve.
The other way of defining the requirement is the gas horsepower equation. Essentially the mass flow rate multiplied by the adiabatic head, again by calculating the pressure right at the beginning of the nozzle before the choke point. This defines how much power is coming out of the start cartridge. Ultimately, we take one of those two numbers as our specification, gas horsepower with time or, pressure with time. From there, we can get an idea of how much energy needs to be in the start cartridge.
Initiation – Two Methods
The next design input is initiation: figuring out what the input signal, that first impetus, will be to get things going.
There are two methods of initiation. The pyro transfer line and electric ignition. The pyro transfer line is the older more traditional or “legacy” method. The picture (Figure 3) shows a Harpoon system where there’s a single initiator into a manifold and those lines are carried down throughout the system. These pyro lines are what carry the energetic signal. On lower left section of the image, you have the start cartridges broken up into a pair. The right side of the picture are pyro initiators. The pyro line concept was driven by the idea of EMI being a real issue, so they have the initiator in a more central, sealed and shielded location. Everything outside of the shielding is immune to radiation and electromagnetic effects because it’s pyro.
We’ve come a long way from the initial pyro line model with the advent of robust electric ignition systems (Figure 4). We have ways of testing EMI now and understand shielding requirements and testing techniques to validate EMI protection that we didn’t before. Because of this, the electric ignition system is now favored over a pyro transfer line system. The electric ignition system has more flexibility and is easier to handle and manage the electric lines. This method tends to be the more modern configuration, but both are still used and are acceptable. PacSci EMC can design with both.
With initiation defined, the next design element is propellant. There are two primary choices: Ammonium Perchlorate based and Ammonium Nitrate based. Both types can provide the energy to spin up a system but there are some preferences to one over the other. On the left (Figure 5) is the ammonium perchlorate base. It’s the more modern composite propellant. The right shows the ammonium nitrate-based material. Both are relatively low efficiency propellants.
Generally, in a rocket propellant, you want a super-hot exhaust with an massive velocity, optimizing the system around stoichiometric chemistry. In a start cartridge, you want to run rich because you want a cooler combustion product than you’d normally see in a rocket engine. You’re still inside a turbine engine and impinging. The gas is directed at the
compressor as opposed to directly into the hot section and those compressor components aren’t generally designed to withstand very high temperatures. We cool the combustion by running it rich. Some of the carbon and by-products can recombine further downstream when air is introduced into the system through the inlet. This can lead to a little extra kick. This is not the primary intent of a rich mixture though; the goal is to cool the exhaust.
There are two major differences between the ammonium perchlorate based system and the ammonium nitrate based system. The ammonium perchlorate base is naturally phase stabilized, meaning that through temperature changes, it doesn’t change its phase. The crystalline structure of the ammonia perchlorate doesn’t expand and contract on its own so it’s very stable. It’s also very moisture resistant. These characteristics make it resemble nice, solid plastic chunks that are easy to work with and easy to store.
Ammonium nitrate is much less forgiving, however there are reasons it has a long history and continues to be used today. There’s a solid understanding of what its limitations are and how to manage and control them. Primarily, the issue is moisture. Typical ammonium nitrate will
expand and contract as it passes through normal storage temperatures like temperature cycling in a bunker or in a ship. This is not a typical coefficient of thermal expansion; it is a change of the crystalline structure driving the propellant to break down mechanically. This turns it back into somewhat of a powder, which gives you a lot more surface area. When
you light off a powdery grain it burns much more quickly than anticipated. This can result in a fast burn and catastrophic failure of the cartridge.
In ammonium nitrate-based propellant, the crystalline structure can be stabilized. As it passes through normal storage temperature, when it’s in that phase stabilized state, it does not change its crystal structure and it remains mechanically stable. However, when it’s exposed to moisture, it loses that phase stabilization, and is then subject to potential failure.
Once the start cartridge is designed, in terms of how much energy is needed and amount of propellant, we work with our customers to package the start cartridge into a shape that fits within their system. We meet their mechanical requirements as well as the specification for
starting the engine and getting it spinning.
The picture (Figure 6) shows a turbine engine used in the MALD system. In the upper right-hand corner is a PacSci EMC start cartridge mounted on the engine. It’s a fairly large package. All the propellant is in a single unit, and you can see trailing off to the to the left is the electric ignition system. The pig tail is attached to a connector that ties it into the rest of the system.
From a slightly different angle (Figure 7) you can see more of the nozzle end. The exhaust from the start cartridge comes out facing the inlet to the engine. A manifold directs it off into two directions. Those two points impinge on the edge of the compressor, which then flow out through the hot section in the engine.
In another example (Figure 8), this is a Teledyne engine from a Harpoon missile. There are two cartridges with pyro initiation system. You can see it’s been divided into two separate packages so that it’s a narrower fitment allowing the fairing to get a little bit tighter around the engine. The nozzle is actually incorporated into the start cartridge and injects directly
against the compressor blade. From there it will flow into the combustion chamber and then out the hot section.
While there are many details, that completes the basic high level design steps used to create a start cartridge. That’s the ‘turn’.
What Are Pyrotechnic Igniters?
Pyrotechnic igniters follow a very similar energetic train in terms of howwe go about designing them and how they perform. In this picture (Figure 9) of the pyro igniter, starting from the left, you have the firing impetus. It travels down the line into a booster charge that essentially amps up that signal.
Then it flows down what we call a spit tube that goes through the center of the grain. There’s an environmental closure at the nozzle, which holds in the pressure from the booster. The flames from the booster are reflected back up toward the grain which hits the ignition enhancement which is more sensitive to lighting off. Once that gets burning, the flame
transfers into the primary grain. Once the grain is lit off, the pressure builds along with a lot of heat, until it compromises the environmental closure, and the exhaust products flow out the nozzle. It’s very similar to the way the start cartridge works just on a much smaller scale.
When it comes to sizing, the process is very similar to start cartridges in that we’re really focused on the amount of energetic material in there and the duration of time it has to burn. What we look for (Figure 10) is the type of ignition, what’s coming in and the energy flow rate that is required to flow out. Generally, the output is specified to us in calories per second,
and the duration of the burn.
Initiation – Two Methods
there should be some familiarity in this process in terms of the harpoon system (Figure 11) driven by a single pyrotechnic event initiation system which then uses transfer lines to drive on to the pyrotechnic igniters. The electric ignition (Figure 12) is the same as a start cart. In many cases, we use the same core components in the initiation of the pyrotechnic igniter that we do in the start cartridge. If you see a cutaway of this, it will look identical in terms of the energetic components. The case is a screw on where the customer’s connector screws directly to the back of the initiator. The other end is the hot side where the solid comes out.
In the start cartridge, the propellant is really optimized around putting out cool gas to get it up and spinning. With the pyrotechnic igniter it’s really about putting out hot particulate matter, or “flame”, making it a bit more exciting in terms of visibility.
In Figure 13 we have an ammonium perchlorate-based solution. This is a sample of a ROFI (radially outward firing igniter) and in this case, it’s heavily doped with aluminum, which puts out the sparklers. There’s a video on YouTube showing this ROFI in action. It’s normally inside a liquid rocket engine, but it’s one of the propellants we use in jet engine starting. This ammonium perchlorate solution is more modern and is traditionally used as a solid rocket fuel.
The MTV (Magnesium Teflon Viton) is the more traditional solution (Figure 14). It’s significantly more energetic in terms of energy per mass, and its output has a lot more solids.
MTV is traditionally used in an IR decoy flare. Very bright, very hot, and it puts out a lot less pressure, which, in this case for a turbine engine start, doesn’t matter as much. It tends to run a little bit denser, and therefore fits in a smaller packaging.
Now it’s on to integration into the engine. In this picture of the harpoon engine (Figure 15), you can see the igniter tucked way in. The start cartridge is up on top but tucked back in the hot section where the combustion chamber is, where the igniter sits.
n the cutaway image (Figure 15) that small igniter pierces through the outer body and into the combustion chamber.
This is also a split system, so the unit is rather small. There’s a mirrored unit on the other side, that’s divided the total required energy into two units.
The final integration of the engine is really the bigger portion of the engineering effort from the standpoint of getting it mechanically packaged and in a way that can fit within a fairing and within the overall envelope of the engine. No matter which engine start device you require, at PacSci EMC, we always prioritize working together with you to meet your
Q: Are the exhaust products considered noncorrosive?
A: The answer is “it depends”. With the AP (ammonium perchlorate) propellant, there is a hydrogen chloride component here and that turns into hydrochloric acid with the introduction of water. So, it is corrosive.
It’s not particularly a problem in a single start setting. But if you were to have a situation where you were to start an engine and run it for awhile, it wouldn’t have too much exposure because most of this gets blown out with the air flow that goes through. But if it were to sit and then start again, months later, it might be a problem.
The AN (ammonium nitrate) Propellant does not have the corrosive component to it. It has a little bit of a base material but it’s not particularly corrosive in that regard. It contains a little bit of ammonia and sodium base salt, which, when dissolved in water, becomes a little bit basic, but it’s not considered corrosive.
Depending on the application and whether you need a non-corrosive material, that might drive the propellant selection in that case.
Q: How many Start cartridges has PacSci EMC developed?
A: Over the years, we’ve gotten to the point of manufacturing for approximately eight different turbine engine start systems. Right now, we currently supply components for six, two of which are at the end of life and essentially will be retired. We have others under development right now that we can’t share too much about but we have several different systems we’re currently working.
Q: Do you sell propellant directly to your customer?
A: There are a few small cases in which we do, but for the most part we’re a component manufacturer and the propellant is selected and designed around an application where the customer has an action problem. They’re looking for work to be performed, whether it’s spinning a turbine or actuating a device or cutting or something of that nature. We tend to focus on that aspect of performing work, as opposed to supplying propellant.
We manufacture our own propellant for the most part. There are some that we purchase and use in products, but typically, we manufacture it onsite and the propellant goes into our designs.
There are a few cases where a customer has a very specialized need and we can’t make it all the way to finished integrated energetic device. However, in most cases we are able to provide a finished part that competes an operational system.
Q: What are the failure rates, and what’s the most common point of failure?
A: In terms of start cartridges it depends on the specific cartridge, but it’s upwards of 0.999 reliability, so it’s extremely low failure rate.
Generally speaking, the failure mode is failing to meet the specification of duration and delivering the energy too quickly.
With the phase stabilization of AN (ammonium nitrate) there is also, in terms of the way the start cartridge is bonded to the outside for the AP (ammonium perchlorate), if you have any sort of cracking or bond line failure, it potentially could lead to a shorter burn. Laying that fast burn issue back on the specification; because it comes as gas horsepower for seconds or pressure for second, what happens is essentially, the cartridge delivers its energy much more quickly than intended.
That may or may not result in a failure of the engine to start, depending on what happens in terms of the rest of the system. For example, if half the time it delivers its energy, when you deliver the energy very quickly, the inertia is harder to overcome. So, the engine doesn’t get spinning as quickly for as long a period, therefore, it could result in a failure to start the engine.
Q: Would you use a phase stabilizer for AN or do you have solutions that allow you to do without a stabilizer? If yes, what type of solution?
A: At the moment, we do not have a solution for phase stabilization of AN. We prefer to procure propellant from the Navy at Indian Head, and through their casting method it achieves phase stabilization. It’s a hot press type of operation, and the end result is a phase stabilized grain that can withstand temperature cycling.
While we certainly have worked on propellant of our own that is phase stabilized, in terms of solutions, ours is not as mature as Indian Head’s.
Q: Target materials can vary quite a bit in mechanical properties for the same material. How does a cutter design account for material property variations in the target?
A: It was chosen because of a high voltage. If it were a metal blade cutting through that high voltage, it would arc back to the blade and reconnect, not doing its job of cutting power to the generator.
Q: What are the customer inputs to select the propellant.
A: In terms of customer inputs to select propellant, it’s that temperature requirement. If they can handle basically the extra 300 degrees of the AP that’s the preferred path. It also depends on the byproducts. If it’s required to have no corrosive materials, then, that drives toward the AN solution. Generally, these two technical elements drive the choices.
One of the challenges of procuring through Indian Head is that nearly every propellant manufacturer has a base batch size. Meaning the mixing equipment and processes are designed around mixing a specific amount of propellant. Deviation from that amount of propellant is frowned upon because there’s potential risks in terms of process, so they tend to like a fixed amount of propellant.
When working with the Navy at Indian Head, it’s a very large amount of propellant. If you want a small number of start cartridges, you must buy a large batch of propellant to try to make that small number of cartridges. So that often tends to be a driving factor, along with turnaround time. Getting in their queue can take a while.
Q: Are there any guidelines on how to select the diameter or the orifice?
A: With the orifice, referring to the choke point of the nozzle, there’s a sweet spot relative to the pressure cartridge performance. It’s a little bit tricky from the standpoint you want to make sure you’re operational and you have pressure equilibrium at temperature. Typically, a cartridge will go to say, let’s say -65 degrees Fahrenheit. The idea being that you’re high in the atmosphere and you’re lighting this thing off and starting it, or you’re at a very cold location, which is basically the temperature bottom end. The propellant burns more slowly at those temperatures, so you need to have a nozzle size that’s tight enough to maintain combustion stability at that low temperature.
At the other end, the higher the pressure of the system, the heavier the case weight and the shorter the burn duration. Generally, a longer burn duration is preferred over a short one, because overcoming that inertia is the goal. So, in terms of the nozzle size, we really work at hitting somewhere between 1000-1500 PSI in terms of the operational pressure at nominal temperature for the motor and for the start cartridges. That balancing act is what really drives the nozzle size.
We have KN tables for our particular propellants and also calculations from Sutton’s Rocket Propulsion Elements. We use those to determine the initial size. Based upon prior batches of propellant and the burn rates of those propellants there’s a little bit of variability. So, there might be a small adjustment that we’ll make based upon imperial tests that we’ll perform on the propellant to establish the burn rate for that particular batch. Every batch is tested for burn rate and mechanical stability. We may tune the nozzle slightly, but generally speaking, once we dial in on a nozzle size, it’s set.
Q: Are there any limits to the size of an engine you can start?
A: When you get down into it, there’s not really an upper limit in terms of the mechanical system and the physics of it. What tends to drive it is practicality. You saw on the Harpoon, and on the Teledyne engine, they tend to be relatively large packages relative to the size of the engine.
We work with our customers to determine what is practical. There is probably an upper practical limit, but there are many things we can do in terms of splitting into multiple packages. If the application is too large for it to be practical, then we come to that determination together and find a solution.
Q: How long is your typical development cycle?
A: It depends on how we approach the design and what it entails. The sizing of the cartridge generally is a fairly quick process. If it’s designing a modification of something we currently have, it could be as little as 6 to 9 months. If it’s casting a new grain and a fully new design with the heavy integration into an engine it could be upwards of 18 months, two
years, potentially even longer. Depending on the propellant choice and availability through Indian Head, the process could go a little bit longer than two years.
Ultimately, it really depends on the customer need and how far we have to go from adaptation of what we currently have versus starting with a full, clean-sheet design.
An example of perseverance.
Bryan Stacey | Business Development Manager
The Stratolaunch ‘carrier aircraft’ project was started in 2010. Multiple aerospace and space launch companies were involved in the early days of the design of the airframe and launch vehicle to transport payloads to low earth orbit.
By 2014, Stratolaunch was looking at multiple launch vehicle options, however, that year Stratolaunch decided to focus the company efforts on the completion of the carrier aircraft. The carrier aircraft would offer a unique, lower cost option access to space. The customer would not be bound by a specific land
launch pad and the customer would save on traditional launch expenditures.
In 2015, Stratolaunch Systems was placed under the leadership
of Paul Allen’s (Microsoft Co-Founder) new aerospace company Vulcan Aerospace. 2015 would be the year Vulcan Aerospace decided to shift how the world conceptualizes space travel through cost reduction and on-demand access. This was not a new concept, but Stratolaunch had a cost-effective delivery system – the carrier aircraft.
Around late 2017, early 2018, PacSci EMC employees visited Stratolaunch’s headquarters in Seattle, WA where we presented our Frangible Joint Assembly for their launch vehicle as well as our Payload Release Sequencing System for deployment of payloads off their launch vehicle. We then proceeded with limited trade studies which were completed in early 2018.
In October 2018, Paul Allen, the source of funds and vision for the company, passed away and in January of 2019 the company halted the development of all air launched space vehicles. Following this, on May 31, 2019, Stratolaunch stopped all operations and was pursuing a complete sale of all its assets.
The PacSci EMC team kept in contact with individuals that moved to different aerospace companies and in December of 2019 a new owner was announced, Cerberus Capital Management. After the announcement of the new owner there was a new vision for the carrier aircraft. The new mission of the carrier aircraft was to provide a high-speed flight test launch platform, i.e., launching
hypersonic test vehicles.
In early 2020, our engineering team was collaborating with the Stratolaunch technical team on providing separation nuts and explosive bolts for the hold down and release of the hypersonic test vehicle named Talon-A (which is released from
the Stratolaunch carrier aircraft). Stratolaunch had tried using traditional missile launch racks, however, the separation nuts and explosive bolts, built out of the PacSci EMC Chandler facility, were exactly the right product for the mission. In addition to providing the separation nuts, explosive bolts, and smart initiators, our Hollister team introduced the Smart Energetics Architecture (SEA) sequencing system as the “brains” behind the initiation of the separation system. In Q4 2020, Stratolaunch placed a purchase order with PacSci EMC for the entire payload release system. During technical meetings, customer visits, etc., we were introduced to the Talon-A engineering team.
The Talon – A hypersonic test vehicle, like all vehicles flown on a US test range, had a need for a flight termination system. Over the course of several months of technical meetings, specification revisions and customer visits to their facility in Mohave, CA, we were awarded the flight termination system for the Hypersonic Test Vehicle. Stratolaunch plans to test up to 60 flights per year,
and we are proud to be part of every vehicle separation and hypersonic vehicle launch.
The first vehicle separation and hypersonic test flight is scheduled for Q2 2022. If you are not following us on our social media platforms, now is the time to follow PacSci EMC for up-to-date notifications and information on this exciting project and future for hypersonic vehicle testing. This is certainly an exciting
time for all involved in the space industry!
UAV’S & ENERGETIC CONTENT
Neal Kerr | Senior Director, Business Development & Jim Lemister | Sr. Director, Business Development
In military parlance, an Unmanned Aerial Vehicle (UAV) or drone is an aircraft which is guided autonomously or by remote control (or both), typically carrying a variety of electronic devices for the purpose of interfering with or destroying enemy targets. Small drones resembling large model airplanes in the 1980’s have advanced to become highly sophisticated high-altitude systems.
An early modern example is the U.S. Air Force MQ-1 Predator. This system was introduced in the 1990’s and was operated by both the USAF and CIA by pilots located thousands of miles away. This system can hover over a target for 14 hours and saw significant service in Afghanistan, Pakistan, Bosnia, Serbia, Iraq, Yemen, Libya & Somalia.
Newer versions of UAV’s include the MQ-1B Predator, RQ-4 Global Hawk, MQ-9 Reaper (USAF) and the MQ-1C Grey Eagle (Army) to name a few.
Their missions are to operate over the horizon at various altitudes for long endurance providing real time intelligence, surveillance, reconnaissance (ISR), target acquisition and strike capability. By far, the largest energetic device on board some of the above UAV’s is the Hellfire missile. Energetic devices on this missile include the safe & arm, rocket motor igniter, rocket motor itself and of course, the warhead. One of these devices to highlight is the safe & arm/arm-fire device. This electro-mechanical assembly prevents an unintended initiation of the rocket motor while the missile is being stored, handled and in flight not yet ready to be armed. As one can understand, the consequences could be catastrophic with an unintended ignition.
As UAV’s become more sophisticated carrying other types of payloads for both commercial and military needs, it’s expected that the use of other energetic devices will be needed. Examples of these products could include cable cutters and various types of actuators used to release payloads or sever other UAV subsystems.
Introduction to Intelligence Studies, 2nd Edition, Jensen, McElreath, GravesUSAF
John Fronabarger: Chemist. Inventor. Inspiration.
This month we have the honor of profiling John Fronabarger, PacSci EMC’s longest-tenured employee. John’s storied career includes recognition as author on over 50 scientific publications and inventor of at least 25 U.S. Patents. Now in his 90’s, he continues to advance the PacSci EMC mission as a part-time employee, inspiring us daily with his unwavering commitment to the field of energetics.
John was born in 1927 in Fredericktown, Missouri to Missouri Photojournalism Hall of Fame photographer Garland Fronabarger and schoolteacher May Fronabarger. In contrast to his parents’ careers, John found his calling in science at an early age. When he was 10, he built a laboratory in the basement of his house to satisfy his curiosity for chemistry, marking the beginning of a lifelong pursuit in the field.
In 1950, John graduated from Southeast Missouri State College in Cape Girardeau with majors in chemistry and mathematics. He then attended graduate school at the University of Missouri, Columbia, majoring in organic chemistry under renowned organic chemist Prof. Norman Rabjohn. Before long, his work was appearing in industry-leading journals. His first article, “β-diethylaminoethyl esters of sterically hindered alkyl substituted benzoic acids,” was published in the Journal of Organic Chemistry in 1955.
John’s expertise in chemistry made him valuable to the energetic materials industry. In 1959, he joined the armament division of Universal Match Corp (which later became Unidynamics), where he developed BI-770, a high temperature bridge ignition replacement for lead styphnate. He was also involved in hotwire initiation studies, electrothermal response testing and field expedient ordinances for the U.S. Army. To top it all off, John helped destroy Classified items to prevent compromise by foreign adversaries – a scene straight out of a James Bond movie!
Starting in 1962, he worked on a number of contracts with Sandia National Labs, preparing over 200 energetic coordination compounds involving at least nine coordinating metals. He was also instrumental in development of the cobalt (III)-based CP series explosives, which have been used in oilfield completion activities, military and commercial aircraft, and nuclear weapons.
John was an employee at Unidynamics when his company was acquired by PacSci EMC in 1993. At PacSci EMC, his notable contributions include synthesizing energetic aromatic and heterocyclic compounds (with emphasis on high nitrogen compounds) and developing pyrotechnics and propellants.
In 1996, NSWC-IH asked him to perform a literature study of potential “green” replacements for lead azide and styphnate. His research led to the development of programs for the primary explosives DBX-1, MTX-1 and KDNP, including detonator, actuator, and gun primer studies.
John’s PacSci EMC resume also includes considerable experience in chemistry and ordnance engineering troubleshooting. This includes failure analysis involving chemical, electrical, and mechanical phenomena, as well as developing conceptual design for ordnance components. Recently, his focus has been on synthesizing ultra-high temperature high nitrogen secondary explosives.
As you can see, John’s legacy here is well-cemented.
Outside of his day job, his accomplishments are lengthy and illustrious. In 2001, he received a NSWC-IH Commendation award for his work on CP use in Tomahawk missiles. In 2006, he was named to the R&D 100 list for his work in “green” energetics. In 2010, the U.S. Navy’s CAD/PAD division recognized him with a Lifetime Achievement Award. John has also served as Treasurer on the Board of Directors of the International Pyrotechnics Society, and as a member of the Steering Committee, International Symposium on Energetic Materials Technology, American Defense Preparedness Association, and American Chemical Society. Most importantly, John is a loving husband to Virginia, his wife of over 50 years!
John has logged over 61 years of experience in the field of energetic materials chemistry, and he shows no signs of slowing down. We’re thankful for everything John has done at PacSci EMC and look forward to his many contributions in the years to come!
Stories from the Field
In addition to his professional accomplishments, John is cherished by his friends and colleagues as both an exceptional mentor and someone who
knows how to have a good time. Read on for some of his acquaintances’ fondest memories.
John the Willing Mentor
When I first came to Unidynamics (Goodyear, Arizona) from Ensign-Bickford (nearly the opposite side of the country in Simsbury, Connecticut), I was introduced to the technical staff, including John. Many of them were either a bit aloof or too busy to talk to newcomers, but John was different.
Early on, he reached down on the floor and handed me six inches of papers, many of them mimeographed notes (yes, mimeographed notes!), and said, “Read these, come back and we’ll talk.” This became a recurring event. One day he asked, “So, you want to go bite a bean?” which was code for “You want to go to lunch with us?” The place was a small Mexican restaurant, where we would sit at the bar, have a cold one and
talk about everything under the sun.
Eventually, he became my mentor in energetic physics, playing a key role in my decision to pursue the rest of my career in the field. During my time under his mentorship he sent me to both Sandia and Los Alamos to meet and learn from the best. I consider this a debt that can never be repaid.
Decades later, I joined John for his 90th birthday at a hotel in Arizona. He truly has made a difference in so many peoples’ lives, and we have been fortunate enough to live part of it with him.
Charles “Chip” M., NASA LSP Ordnance Engineering
John the Inspiration
Even though I only officially worked alongside John at Unidynamics for eight months in 1991-1992, he has ended up being the most consequential mentor I have had in my career as a chemist. Since my time at Unidynamics, I’ve been fortunate to work with John on two SBIR projects at TPL Inc., and then on several projects at the Naval Air Warfare Center Weapons Division (China Lake) via Cooperative Research and Development Agreements (CRADAs) with PacSci EMC.
Through many technical interactions with him, as well as seeing his success in developing products that are incorporated into real-world systems, I’ve come to believe that John is probably the single most valuable energetic materials chemist our country has had in recent decades.
We’re all lucky that John has chosen to keep working, even at 94 years old. I’m privileged to have played a small part in exposing the more “basic” research-oriented energetic materials community to John by getting him to attend some of their regular meetings, such as the Gordon Research Conference on Energetic Materials. There, he’s been able to meet scientists who rarely attend the more “application-soriented”
conferences that John is used to, such as those of the ADPA.
Robert C., Ph.D. (NAWCWD China Lake 1995-2015)
John the Entertainer
John once told me that when he was a young’un back at Crab Orchard, they used to have lots of hot plates on at various temperatures that people would sprinkle powders on to gauge an approximate autoignition level. He also said they were into stab primers at the time and had several drop testers for pull string/pin initiation. When an old-timer saw John ogling at the stab primer tester, he asked him if he wanted to try it. John got a bit excited and yanked the firing string so hard that he pulled the entire test machine off the hood and onto the floor!
Alex S., Senior Chemist (Unidynamics/Phoenix 1990-1994)
ANSWERS TO ROCKET SCIENTIST’S READING LIST | VOLUME 2 NO. 2
A. Albert Einstein: A Biography
B. An Astronaut’s Guide to Life
C. The Autobiography of Benjamin Franklin
D. Structures: Or Why Things Don’t Fall Down
E. Rocket Propulsion Elements
F. Ignition!: An Informal History of Liquid Rocket Propellants
G. Modern Engineering for Design of Liquid Propellant Rocket Engines
H. Elements of Propulsion: Gas Turbines and Rockets
I. Set Phasers on Sun
J. Fundamentals of Astrodynamics
K. Watership Down
L. The Hitchhiker’s Guide to the Galaxy
M. How to Fail at Almost Everything and Still Win Big
N. The Moon is a Harsh Mistress
O. If the Universe is Teeming with Aliens… WHERE IS EVERYBODY?